Caliper brake assemblies used to apply frictional braking force to a rimmed bicycle wheel are commonplace. FIG. 1 illustrates such a device. Specifically, a shaft appended to hexagonal nut 11 is mounted on the bicycle frame. Helical or torsion spring 13 is inserted as shown and serves to keep brake shoes 12 away from the bicycle wheel to prevent frictional braking unless braking action is applied, usually through the actuation of a hand brake assembly causing movement of cable 5. In applying braking action, brake stirrups 17 and 18 pivot along a bolt behind hex nut 11 drawing brake pads 12 against their associated wheel rim. When the hand brake assembly is released, cable 5 is extended causing brake pads 12 to move apart through the action of bias spring 13.
In operating with the assembly of FIG. 1, it is quite apparent that the extent of braking force is directly proportionally to the force applied through associated hand brakes as translated through cable 5. As a consequence, there has been some thought given to increasing the mechanical advantage between the force applied to hand brakes and the consequent frictional contact between the brake pads and wheel rim.
As an illustration, reference is made to U.S. Pat. No. 3,628,635 as well as U.S. Pat. No. 7,000,739. In each instance, cam mechanisms were disclosed in order to provide a mechanical advantage in translating force developed from a braking operation to the actual braking mechanism. However, these brakes tend to be complex, unduly heavy and create frictional resistance far greater than that imposed by traditional caliper brakes. As such, there is yet to be a practical solution to the need for translating hand applied braking action through a mechanical advantage to a caliper brake positioned adjacent a bicycle wheel.
It is thus an object of the present invention to provide a caliper brake for use with a bicycle wheel rim which results in a mechanical advantage while avoiding the drawbacks of prior art.
This and further advantages are more readily apparent when considering the following disclosure and appended claims.